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Jandy valve makes a knocking noise

If I quickly turn my jandy valve from dedicated pool side vac to skimmer operation I can hear what sound like a ball **** knocking noise in the pipes. Is this normal or is a golf ball or something stuck in there? Thanks.

Re: Jandy valve makes a knocking noise

Thanks. Yes I normally turn valve slowly from pool side vac to skimmer. I thought I may have a blockage as if I turn it slowly even to pool side vac I get more air bubbles in the pool pump basket. Hence the quick turns to see if could dislodge if something was there.

Re: Jandy valve makes a knocking noise

I have similar noises when turning valves. I don't believe it's from anything in the lines. Think it's either some shock wave from the changes in flow as Brushup described or oil-canning or other type of flexing of parts in the pumping system. I think it's fairly harmless and can be ignored.

Re: Jandy valve makes a knocking noise

Originally Posted by gtemkin

I have similar noises when turning valves. I don't believe it's from anything in the lines. Think it's either some shock wave from the changes in flow as Brushup described or oil-canning or other type of flexing of parts in the pumping system. I think it's fairly harmless and can be ignored.

Re: Jandy valve makes a knocking noise

Yup. JamesW is right. Its water hammer. He is also correct in recommending to turn off the pump before moving the valves. Over a period of years, the water hammer can potentially cause the pipe and/or valve to fail.

What happens is when the water "hammers" it very very slowly etches away at the interior of the pipe and eventually, when the wall becomes thin enough and the pressure high enough, it will burst. http://en.wikipedia.org/wiki/Water_hammer

Re: Jandy valve makes a knocking noise

Thanks. I won't be sliding the valve back and forth like that again. Only did it a few times. I normally slowly turn the valve to center area to get floor vac and skimmer both on at same time. After changing the weir I've noticed weaker skimmer flow on the side closest to pool pump. Irony being the further away skimmer hardly ever shifted water. Now they both seem to work equally. Albeit the closer one to pump slightly weaker.

Re: Jandy valve makes a knocking noise

I grew up in a old house that had a water hammer problem. Every time a faucet was turned off, the pipes would rattle.
I think I was 13 or 14 when the pipe finally burst.

My irrigation system has some water hammer but only one 1 zone. Everytime that valve closes, it rattles like crazy.

Funny you say this. My water heater inside home is about ten years old. Every time a faucet is turned on or off I can hear a ball or something hitting inside the pipes which reverbs through house copper pipes. I'm assuming this is normal. I've only been living in USA since 2007. Specs might be different to UK.

Re: Jandy valve makes a knocking noise

yup. Thats it. I guarantee it.

And no, water hammer is not expected. Most often water hammer is a result of a poorly designed plumbing system or perhaps properly designed and the plumber didnt adhere to it. *most likely the case*.
There are building codes in the US that are supposed to prevent this from happening. On houses from the 60's and earlier though, water hammer is a fairly common occurrence.

Originally Posted by Limey

Funny you say this. My water heater inside home is about ten years old. Every time a faucet is turned on or off I can hear a ball or something hitting inside the pipes which reverbs through house copper pipes. I'm assuming this is normal. I've only been living in USA since 2007. Specs might be different to UK.

Re: Jandy valve makes a knocking noise

Originally Posted by Divin Dave

yup. Thats it. I guarantee it.

And no, water hammer is not expected. Most often water hammer is a result of a poorly designed plumbing system or perhaps properly designed and the plumber didnt adhere to it. *most likely the case*.
There are building codes in the US that are supposed to prevent this from happening. On houses from the 60's and earlier though, water hammer is a fairly common occurrence.

Sorry for straying off topic. Yes, hopefully the water hammer issue from water tank won't loosen all my plumbing house was built in 89.
Code you mentioned? I say to myself what code when I walk the attic and see electrical wires all over. Crazy.

Re: Jandy valve makes a knocking noise

Originally Posted by Limey

Funny you say this. My water heater inside home is about ten years old. Every time a faucet is turned on or off I can hear a ball or something hitting inside the pipes which reverbs through house copper pipes. I'm assuming this is normal. I've only been living in USA since 2007. Specs might be different to UK.

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I can confirm that this happens....and that you should decidedly NOT consider it normal. In a former house, I had quite some water hammer that I was able to deduce had something to do with one of those back flow prevention devices they require on outside hose bibs. Like you, I thought this could be normal.

One particular Saturday afternoon, I washed my truck with the hose attached to this particular "noisy" spigot. Fathers' Day 2012 is a day that I shall never forget. I was awoken at 4:00 Sunday morning with 4 inches of water covering the floor of everything downstairs. It turns out that my water hammer ruptured my main water line in the attic right before it branched off to the water heaters. We had to live in a hotel for a few weeks while they dried out the house and put in all new sheetrock and trim downstairs. $42,000 later, the house was as good as new. The only good part was that the house was brand-new and we were still within the 1-year bumper-to-bumper builder warranty.